Obese patients in the Veterans Administration health system who underwent bariatric surgery had lower all-cause mortality 5 and 10 years after the procedure than did matched patients who didn’t have bariatric surgery, according to a report published online Jan. 5 in JAMA.
In a retrospective cohort study of severely obese VA patients across the country, 2,500 who underwent bariatric surgery during 2000-2011 were matched for body mass index (BMI), age, sex, diabetes status, race, and area of residence with 7,462 who did not. The mean age of the study participants was 52-53 years, and the mean BMI was 46-47, said Dr. David E. Arterburn of the Group Health Research Institute and the University of Washington, both in Seattle, and his associates.
During a mean follow-up of approximately 7 years, there were 263 deaths in the surgical group and 1,277 in the control group. Estimated all-cause mortality was 6.4% at 5 years and 13.8% at 10 years for surgical patients, compared with 10.4% and 23.9%, respectively, for control subjects. Bariatric surgery was not associated with any difference in mortality for the first year of follow-up but was associated with lower mortality at 1-5 years (hazard ratio, 0.45) and at 5 or more years (HR, 0.47) of follow-up, the investigators said (JAMA 2015 January 5 [doi:10.1001;jama.2014.16968]). Over time, the association between bariatric surgery and lower mortality did not change even though criteria for patient selection and types of bariatric procedures did. And the association remained robust across several subgroups of patients, including patients who did and patients who did not have diabetes.
This VA study population was predominantly male and middle-aged, so the findings expand the evidence of bariatric surgery’s mortality benefit beyond that observed in previous studies of predominantly younger, female populations, Dr. Arterburn and his associates said.
This was a retrospective, nonrandomized, observational study, so the association identified between bariatric surgery and improved mortality cannot be considered causal on the basis of these results. “Only randomized clinical trials could provide definitive evidence that bariatric surgery improves survival,” but large enough RCTs would be very difficult to conduct and prohibitively expensive. So, at least for the present, both clinicians and patient must rely on observational research results such as those from this study to inform their treatment decisions regarding bariatric surgery, the investigators added.